Siglent SDS800X HD Review & Demonstration Thread

[Performa01]

Here is the second part, including the following main topics:

MSO
HAM Test
User Comments

Figures
Tables

[eTobey]

...

On page 23 you wrote: "At 5 μs/div, the SDS824X HD takes an average of 650 μs/frame and a maximum of <2 ms/frame." I dont get what these 650us/frame mean. I would think it would be a constant 50us as you can see on the screen?

[2N3055]

...

On page 23 you wrote: "At 5 μs/div, the SDS824X HD takes an average of 650 μs/frame and a maximum of <2 ms/frame." I dont get what these 650us/frame mean. I would think it would be a constant 50us as you can see on the screen?

At 5µs/div  50µs is interval shown on the screen.
To do that scope has to trigger, capture, process signal, display and all measurements, and reconfigure to get ready to get another trigger.
That is called retrigger time.
Retrigger time hence consist of time when actual capture is happening and so called "blind" time, while scope processes data and going back to Ready status.

So that sentence means that that when scope is in 5µs/div retrigger time is 650µs/MAX 2ms
Full table of retrigger times(triggers/s) is on pg. 24.

Make note that with same settings, in sequence mode retrigger time is 52us, meaning "blind time" is 2µs.

That is why it is recommended to use sequence mode if you need to capture fast bursts of signal.

[BRZ.tech]

Hi,
Dear @Performa01
I return with the “Newbie” questions.
I am studying how to measure the Slew Rate of an Operational Amplifier in a DSO/MSO.
In this case, I thought this video from Texas Instruments was really good:
https://www.ti.com/video/4078676441001#:~:text=Slew%20rate%20is%20defined%20as,of%20the%20output%20signal's%20amplitude

In order not to waste time, TI defined what the Slew Rate is (time 0min:28sec), and that the “Unit” of measurement is (V/us), photo attached.
TI presented the Slew Rate of different Operational Amplifiers (time 04min:05sec), photo attached.

In the SDS800X HD datasheet, on page 16, in “Horizontal Paramenters” and “Miscellaneous Parameters”, it does not state that it automatically measures Slew Rate.
But it states in “Miscellaneous Parameters” that it automatically measures Positive Slope and Negative Slope.
In the SDS800X HD datasheet, on page 17, it states in “Power Analysis” (optional): “Measure”, which automatically measures the Slew Rate.

In the SDS800X HD datasheet, on page 06, “Parameter Statistics Function”, photo attached, that shows the measurement of a Square Wave Signal of Amplitude = 5Vpp, and f = 10MHz.
In the “PSlope(C1)” column, it presents the “average value”, with: (Mean = 1.0282K V/us), which is extremely fast for an Operational Amplifier, considering data from the best TI OA, according to the attached table.

“Newbie” Questions:
1. Carry out a test with the SDS800X HD, with Square Wave excitation, with Amplitude = 5Vpp and f = 10MHz, repeating the test of: “Parameter Statistics Function”.
Perform the measurement in “Unit”: (V/us), “Slew Rate” and “Positive Slope”.
If there are, explain what are the differences between the “Slew Rate” and “Positive Slope” measurements?

2. Regarding the “Slew Rate” and “Positive Slope” measurements, the performance measurement of the Operational Amplifier, is or is not, the same thing as performing the “Power Analysis” (optional) of the SMPS, for the automatic measurement of Slew Rate?
If they are different, I suggest SIGLENT add the Slew Rate measurement to the SDS800X HD menu, “Horizontal Parameters”.

Anyone on the topic can comment on my questions.
Translation with Google Translate.
Grateful for the attention.

[2N3055]

Hi,
Dear @Performa01
I return with the “Newbie” questions.
I am studying how to measure the Slew Rate of an Operational Amplifier in a DSO/MSO.
In this case, I thought this video from Texas Instruments was really good:
https://www.ti.com/video/4078676441001#:~:text=Slew%20rate%20is%20defined%20as,of%20the%20output%20signal's%20amplitude

In order not to waste time, TI defined what the Slew Rate is (time 0min:28sec), and that the “Unit” of measurement is (V/us), photo attached.
TI presented the Slew Rate of different Operational Amplifiers (time 04min:05sec), photo attached.

In the SDS800X HD datasheet, on page 16, in “Horizontal Paramenters” and “Miscellaneous Parameters”, it does not state that it automatically measures Slew Rate.
But it states in “Miscellaneous Parameters” that it automatically measures Positive Slope and Negative Slope.
In the SDS800X HD datasheet, on page 17, it states in “Power Analysis” (optional): “Measure”, which automatically measures the Slew Rate.

In the SDS800X HD datasheet, on page 06, “Parameter Statistics Function”, photo attached, that shows the measurement of a Square Wave Signal of Amplitude = 5Vpp, and f = 10MHz.
In the “PSlope(C1)” column, it presents the “average value”, with: (Mean = 1.0282K V/us), which is extremely fast for an Operational Amplifier, considering data from the best TI OA, according to the attached table.

“Newbie” Questions:
1. Carry out a test with the SDS800X HD, with Square Wave excitation, with Amplitude = 5Vpp and f = 10MHz, repeating the test of: “Parameter Statistics Function”.
Perform the measurement in “Unit”: (V/us), “Slew Rate” and “Positive Slope”.
If there are, explain what are the differences between the “Slew Rate” and “Positive Slope” measurements?

2. Regarding the “Slew Rate” and “Positive Slope” measurements, the performance measurement of the Operational Amplifier, is or is not, the same thing as performing the “Power Analysis” (optional) of the SMPS, for the automatic measurement of Slew Rate?
If they are different, I suggest SIGLENT add the Slew Rate measurement to the SDS800X HD menu, “Horizontal Parameters”.

Anyone on the topic can comment on my questions.
Translation with Google Translate.
Grateful for the attention.

Short answer, yes, [Positive slope] is slew rate measurement of positive going signal and [Negative slope] is respectively is slew rate measurement of negative going signal.

[Performa01]

Slew Rate Measurement

In the SDS800X HD datasheet, on page 06, “Parameter Statistics Function”, photo attached, that shows the measurement of a Square Wave Signal of Amplitude = 5Vpp, and f = 10MHz.
In the “PSlope(C1)” column, it presents the “average value”, with: (Mean = 1.0282K V/us), which is extremely fast for an Operational Amplifier, considering data from the best TI OA, according to the attached table.

I’ve had a look at Texas Instruments and have found no less than 57 operational amplifiers capable of a Slew Rate of 2 kV/µs or faster. There are still 13 OpAmps with a Slew Rate faster than 5 kV/µs, the fastest being the THS3491, which manages 8000 V/µs.

In the light of this, 1000 V/µs would have required a fast hybrid amp in the Seventies of last century, but isn’t particularly fast for a monolithic integrated OpAmp today.

1. Carry out a test with the SDS800X HD, with Square Wave excitation, with Amplitude = 5Vpp and f = 10MHz, repeating the test of: “Parameter Statistics Function”.
Perform the measurement in “Unit”: (V/us), “Slew Rate” and “Positive Slope”.
If there are, explain what are the differences between the “Slew Rate” and “Positive Slope” measurements?

It needs not be complicated. Here’s a 10 ns wide pulse with 2 ns rise-time, which is at the edge of accurate measurements with an SDS824X HD:


SDS824X HD_Slew_Pulse_W10ns_RT2ns

As can be seen, the rise-and fall-times are accurately measured as ~2 ns. The slew rate should be 80% * 5 V / 0.002 µs = 4 V / 0.002 µs = 2 kV/µs. The actual measurement is off by some 2.76% for the positive slope.

It should be kept in mind that the universal definition of the thresholds to be at 10% and 90% might not be valid in every industry, hence these thresholds are user-definable – see the measurement config submenu displayed in the above screenshot.

2. Regarding the “Slew Rate” and “Positive Slope” measurements, the performance measurement of the Operational Amplifier, is or is not, the same thing as performing the “Power Analysis” (optional) of the SMPS, for the automatic measurement of Slew Rate?
If they are different, I suggest SIGLENT add the Slew Rate measurement to the SDS800X HD menu, “Horizontal Parameters”.

It is all the same thing – Slew Rate is Slew Rate, universally defined in volts per second, no matter what package uses this measurement. Positive and negative slope measurements just measure the Slew Rate on positive and negative transitions.

[pdenisowski]

“Newbie” Questions:
1. Carry out a test with the SDS800X HD, with Square Wave excitation, with Amplitude = 5Vpp and f = 10MHz, repeating the test of: “Parameter Statistics Function”.
Perform the measurement in “Unit”: (V/us), “Slew Rate” and “Positive Slope”.
If there are, explain what are the differences between the “Slew Rate” and “Positive Slope” measurements?

2. Regarding the “Slew Rate” and “Positive Slope” measurements, the performance measurement of the Operational Amplifier, is or is not, the same thing as performing the “Power Analysis” (optional) of the SMPS, for the automatic measurement of Slew Rate?

Anyone on the topic can comment on my questions.

I recently made a short (< 6 min) video on slew rate measurements using an oscilloscope (primarily in the context of switch mode power supplies).  It's the same measurement (delta_V/t) regardless of whether you're measuring an op amp or SMPS, although the way you acquire the voltage waveform may be different depending on the application.

Slew rate is often included in "power analysis" option packages, but in my experience, most people just measure it "by hand" and don't really require a special option to do it.

[Vitold]

Sorry if this is the wrong place to post, but I have a question about SDS800X trigger terminologie.

For dropout trigger type, trigger is configured with "State" for "Over Time Type" But menu says "Slope Rising | Falling"  I think it should be "Time High" and "Time Low" when "Over Time Type" = "State" (and "Rising" or "Falling" when Over Time Time = "Edge") This is confusing for me.

Do other users have the same idea?

Trigger works perfectly, only configuration parameter name is confusing 

[Vitold]

It is all the same thing – Slew Rate is Slew Rate, universally defined in volts per second, no matter what package uses this measurement. Positive and negative slope measurements just measure the Slew Rate on positive and negative transitions.

I have a question about "slope" trigger on SDS800X. This is the same as "slew rate" trigger on other scopes, correct?

When I try to configure a "Slope" trigger, GUI says "Trigger when edge crosses two thresholds is inside or outside a selected time range". I can configure time range, but where can I configure upper and lower voltage thresholds? Or is this not really a slew rate trigger (like on other scopes)?

[Performa01]

For dropout trigger type, trigger is configured with "State" for "Over Time Type" But menu says "Slope Rising | Falling"  I think it should be "Time High" and "Time Low" when "Over Time Type" = "State" (and "Rising" or "Falling" when Over Time Time = "Edge") This is confusing for me.

The terminology is correct. The Dropout Trigger watches for a transition within the specified Dropout time period. A transition can either be rising or falling. The trigger fires whenever the specified transition does not occur within the Dropout period.

I have a question about "slope" trigger on SDS800X. This is the same as "slew rate" trigger on other scopes, correct?

When I try to configure a "Slope" trigger, GUI says "Trigger when edge crosses two thresholds is inside or outside a selected time range". I can configure time range, but where can I configure upper and lower voltage thresholds? Or is this not really a slew rate trigger (like on other scopes)?

It would be effectively the same as a slew rate trigger, but maybe specified differently.

As always, the thresholds are set by the trigger knob. Since there are now two of them, you can push the trigger knob in order to toggle between the two thresholds.

In the attached screenshot, I’ve used Slope Trigger to trigger on the end of the sweep of a 1 Vpp sine wave. Sweep time is 100 ms and frequency range is 100 kHz to 1 MHz. Trigger condition is for a positive signal slope (rising) of less than or equal to 132 ns between -200 mV and +200 mV thresholds. This way, only the 1 MHz sine has a fast enough edge to trigger.


SDS824X HD_Trigger_Slope_1MHz

[Vitold]

As always, the thresholds are set by the trigger knob. Since there are now two of them, you can push the trigger knob in order to toggle between the two thresholds.

That is the thing I was missing - thank you!

[Vitold]

I am sorry for all the questions, but I have my new SDS800X and I am experimenting with it - fun!

Why does it have "GPIB" in I/O Setting? I don't see a GPIB interface on the back of the scope.

[Martin72]

This question is better placed in the general thread:

https://www.eevblog.com/forum/testgear/siglent-sds800x-hd-12-bit-dsos-coming/

[tautech]

I am sorry for all the questions, but I have my new SDS800X and I am experimenting with it - fun!

Why does it have "GPIB" in I/O Setting? I don't see a GPIB interface on the back of the scope.

To support Siglents USB to GPIB adapter:

[pdenisowski]

For dropout trigger type, trigger is configured with "State" for "Over Time Type" But menu says "Slope Rising | Falling"  I think it should be "Time High" and "Time Low" when "Over Time Type" = "State" (and "Rising" or "Falling" when Over Time Time = "Edge") This is confusing for me.

The terminology is correct. The Dropout Trigger watches for a transition within the specified Dropout time period. A transition can either be rising or falling. The trigger fires whenever the specified transition does not occur within the Dropout period.

I wonder if some of the confusion might be from the word "dropout" - some vendors (including R&S and also Tek, I believe) have a "timeout" trigger that triggers when the waveform stays above or below a given level for X amount of time.  There doesn't need to be a transition (i.e. a "slope") for the trigger to occur.  For example, I might want the scope to trigger if a line stays low for more than N seconds.

I presume the Siglent trigger works the same way (and the poster says it does work), just different terminology.

Out of all the T&M instruments I work with, scopes seem to be the least consistent in terminology between vendors.

[2N3055]

For dropout trigger type, trigger is configured with "State" for "Over Time Type" But menu says "Slope Rising | Falling"  I think it should be "Time High" and "Time Low" when "Over Time Type" = "State" (and "Rising" or "Falling" when Over Time Time = "Edge") This is confusing for me.

The terminology is correct. The Dropout Trigger watches for a transition within the specified Dropout time period. A transition can either be rising or falling. The trigger fires whenever the specified transition does not occur within the Dropout period.

I wonder if some of the confusion might be from the word "dropout" - some vendors (including R&S and also Tek, I believe) have a "timeout" trigger that triggers when the waveform stays above or below a given level for X amount of time.  There doesn't need to be a transition (i.e. a "slope") for the trigger to occur.  For example, I might want the scope to trigger if a line stays low for more than N seconds.

I presume the Siglent trigger works the same way (and the poster says it does work), just different terminology.

Out of all the T&M instruments I work with, scopes seem to be the least consistent in terminology between vendors.

I agree about terminology not having industry wide consensus...
And that can be confusing sometimes...

As for word dropout it is a valid signal condition and used a lot.  In communications, power electronics...

[ebastler]

As for word dropout it is a valid signal condition and used a lot.  In communications, power electronics...

"Dropout" is obviously a valid and established term. But it covers only part of the scenarios well where this trigger type might be used. E.g. when monitoring a communication protocol, one may be interested in situations where it takes one station a certain (longer than usual) time to respond. There is nothing missing in the signal, no "dropout" in this case.

So I think "timeout" is the better designation here since it is more general.

[Performa01]

For dropout trigger type, trigger is configured with "State" for "Over Time Type" But menu says "Slope Rising | Falling"  I think it should be "Time High" and "Time Low" when "Over Time Type" = "State" (and "Rising" or "Falling" when Over Time Time = "Edge") This is confusing for me.

The terminology is correct. The Dropout Trigger watches for a transition within the specified Dropout time period. A transition can either be rising or falling. The trigger fires whenever the specified transition does not occur within the Dropout period.

I wonder if some of the confusion might be from the word "dropout" - some vendors (including R&S and also Tek, I believe) have a "timeout" trigger that triggers when the waveform stays above or below a given level for X amount of time.  There doesn't need to be a transition (i.e. a "slope") for the trigger to occur.  For example, I might want the scope to trigger if a line stays low for more than N seconds.

I presume the Siglent trigger works the same way (and the poster says it does work), just different terminology.

Just think of it: in order to leave the low state in your example, there has to be a transition, right? And if that transition does NOT occur within the specified amount of time, then the trigger will fire.

However the Siglent dropout trigger has two modes of operation: State and Edge.

Yes, in case of Edge the Slope switch (Rising/Falling) is not quite right and should change to State (High/Low). The difference is that with State we actually trigger if there is no transition at all within the specified timeout period, whereas with Edge there might be still one additional transition that is the opposite to the trigger condition and consequently the final signal state might be high or low, but the relevant part is that the specified state change or transition does not occur within time.

EDIT: I've just requested an UI-change to get an adapted switch in State mode.

[2N3055]

As for word dropout it is a valid signal condition and used a lot.  In communications, power electronics...

"Dropout" is obviously a valid and established term. But it covers only part of the scenarios well where this trigger type might be used. E.g. when monitoring a communication protocol, one may be interested in situations where it takes one station a certain (longer than usual) time to respond. There is nothing missing in the signal, no "dropout" in this case.

So I think "timeout" is the better designation here since it is more general.

Timeout is "giving up on waiting for something we consider valid to come". It is maybe too general.

Dropout mostly implies completely missing signal or signal that drops out below defined threshold...

For your example,  there is no signaling (voltage transitions) most of the time, unless a side transmits something. What is idle voltage doesn't matter, because we know what idle voltage is considered inactive. In that case you can use Edge, Pulse, Interval or Dropout trigger.....

[eTobey]

I found this interesting information:

For complete information, here are my measurements for the trigger rates during normal use with vector and dots display mode as well as sequence recording from the fastest timebase of 1 ns/div up to 100 µs/div.


SDS824X HD Trigger rate

Can someone please explain, why is there a discontinuity in the rate?

[tautech]

Dropout mostly implies completely missing signal or signal that drops out below defined threshold...

No, this is defined as a Runt.

[ebastler]

Can someone please explain, why is there a discontinuity in the rate?

Could you please be more specific? What do you find unexpected? At which timebase setting(s)?

Edit: What I personally find unexpected is that the waveforms/s do not keep increasing monotonously as we go to faster time bases, i.e. reading the table bottom-to-top. I would expect them to do that, maybe saturating at some point, when the frame time becomes dominated by the post-processing and trigger re-arming time.

Instead the waveform rates keep increasing as we go from slow time bases to 50 ns/div, then start to drop again. Not a "discontinuity", but a non-monotonous behavious which is not obvious.

[gf]

Instead the waveform rates keep increasing as we go from slow time bases to 50 ns/div, then start to drop again. Not a "discontinuity", but a non-monotonous behavious which is not obvious.

Isn't that the point where interpolation joins in in order to display the trace?

[ebastler]

Instead the waveform rates keep increasing as we go from slow time bases to 50 ns/div, then start to drop again. Not a "discontinuity", but a non-monotonous behavious which is not obvious.

Isn't that the point where interpolation joins in in order to display the trace?

But the non-monotonous change applies in dot mode as well. Interpolation should not be relevant there? And for the digital triggering I assume interpolation is used at any time base?

[eTobey]

Edit: What I personally find unexpected is that the waveforms/s do not keep increasing monotonously as we go to faster time bases, i.e. reading the table bottom-to-top. I would expect them to do that, maybe saturating at some point, when the frame time becomes dominated by the post-processing and trigger re-arming time.

Not a "discontinuity", but a non-monotonous behavious which is not obvious.

Figured it out memory limit is reached and as you described the "overhead".

Yes, "discontiuity" was the wrong word.